Anticholinergics in Chronic Asthma: A Promising Future?

Anticholinergics have been used for the treatment of asthma as bronchodilators for centuries, yet they have not gained U.S. Food and Drug Administration approval for use in asthma. Previous studies with the short-acting inhaled anticholinergics, ipratropium bromide, oxitropium bromide, and atropine methonitrate, have failed to demonstrate improved outcomes in chronic persistent asthma. Ipratropium bromide is recommended by national and international guidelines for the adjunctive treatment of severe acute asthma exacebations in the emergency department to reduce hospitalizations. A recent trial reported that the long-acting anticholinergic, tiotropium bromide, in those adult patients not adequately controlled on inhaled corticosteroid monotherapy improved impairment outcomes of lung function and symptoms compared to doubling the dose of inhaled corticosteroid similar to the effect of the addition of a long-acting β₂ agonist. More studies are needed to determine whether tiotropium bromide can reduce the risk of asthma exacerbations, but the early results from the first study are promising.